<!DOCTYPE html>
<html>

<head lang="en">
    <meta charset="UTF-8">
    <title>吃豆人V01</title>
</head>

<body>
    <canvas id="canvas" width="500px" height="500px" style="border: 1px solid black"></canvas>
    <script>
    var canvas = document.getElementById("canvas");
    var context = canvas.getContext("2d");

    //TODO 面向对象方式解析
    //TODO 1.创建吃豆人的对象模板
    function Pacman(){
        //TODO 属性
        this.isOpen = true;//TODO 开关
        this.start = 45*Math.PI/180;
        this.end = 315*Math.PI/180;
        //TODO 方法
        //TODO 1.绘制方法
        this.paint = function(){
            //TODO 吃豆人的脸
            context.beginPath();
            context.arc(250,200,100,this.start,this.end);
            context.lineTo(250,200);
            context.closePath();
            context.fillStyle = "yellow";
            context.fill();
            context.stroke();

            //TODO 吃豆人的眼睛
            context.beginPath();
            context.arc(250,150,15,0,Math.PI*2);
            context.fillStyle = "black";
            context.fill();

            //TODO 吃豆人的眼神
            context.beginPath();
            context.arc(255,145,5,0,Math.PI*2);
            context.fillStyle = "white";
            context.fill();
        }
        //TODO 2.控制开闭切换
        this.open = function(){
            if(this.isOpen){//TODO 开口
                this.start = 45*Math.PI/180;
                this.end = 315*Math.PI/180;
                this.isOpen = false;
            }else{//TODO 闭口
                this.start = 0;
                this.end = Math.PI*2;
                this.isOpen = true;
            }
        }
    }
    //TODO 创建吃豆人的对象
    var pacman = new Pacman();

    //TODO 核心控制器
    setInterval(function(){
        context.clearRect(0,0,canvas.width,canvas.height);

        pacman.paint();
        pacman.open();
    },200);
</script>
</body>

</html>